51 lines
1.4 KiB
Plaintext
51 lines
1.4 KiB
Plaintext
# 2017-02-15
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#
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# The author disclaims copyright to this source code. In place of
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# a legal notice, here is a blessing:
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#
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# May you do good and not evil.
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# May you find forgiveness for yourself and forgive others.
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# May you share freely, never taking more than you give.
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#
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#***********************************************************************
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#
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# Test cases to show that a join involving an empty table is very fast.
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#
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set testdir [file dirname $argv0]
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source $testdir/tester.tcl
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# Build some test data
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#
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do_execsql_test emptytable-100 {
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CREATE TABLE t1(a);
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WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<100)
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INSERT INTO t1(a) SELECT x FROM c;
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CREATE TABLE empty(x);
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SELECT count(*) FROM t1;
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} {100}
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# Interrupt queries after 1M cycles to prevent burning excess CPU
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proc stopDb {args} {
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db interrupt
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}
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db progress 1000000 {stopDb}
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# Prior to the query planner optimization on 2017-02-15, this query would
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# take a ridiculous amount of time. If that optimization stops working,
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# the result here will be in interrupt for running too long.
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#
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do_catchsql_test emptytable-110 {
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SELECT count(*) FROM t1, t1, t1, t1, t1, t1, empty;
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} {0 0}
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do_catchsql_test emptytable-120 {
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SELECT count(*) FROM t1, t1 LEFT JOIN empty;
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} {0 10000}
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do_catchsql_test emptytable-121 {
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SELECT count(*) FROM t1, t1 LEFT JOIN t1, empty;
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} {0 0}
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finish_test
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